Add a rootfs filesystem to fs benchmarks. Also, fix fio benchmark.

The previous "bind" filesystem, already included in go/runsc-benchmarks
is a remote re-validate mount. However, the non-re-validate mount
was not present, and it has been added in the form of rootfs.

Also, fix the fio runs to reads/writes of 10GB as running
with --test.benchtime=Xs may scale beyond the memory available
to tmpfs mounts on buildkite VMs. Currently, our buildkite
pipelines are run on e2-standard-8 machines with 32GB of memory,
allowing tmpfs mounts to safely be at least 10GB.

PiperOrigin-RevId: 362143620

2 files changed, 53 insertions, 0 deletions

diff --git a/test/benchmarks/harness/BUILD b/test/benchmarks/harness/BUILD
index c2e316709..116610938 100644
--- a/test/benchmarks/harness/BUILD
+++ b/test/benchmarks/harness/BUILD
@@ -14,5 +14,6 @@ go_library(
     deps = [
         "//pkg/test/dockerutil",
         "//pkg/test/testutil",
+        "@com_github_docker_docker//api/types/mount:go_default_library",
     ],
 )
diff --git a/test/benchmarks/harness/util.go b/test/benchmarks/harness/util.go
index aeac7ebff..36abe1069 100644
--- a/test/benchmarks/harness/util.go
+++ b/test/benchmarks/harness/util.go
@@ -18,8 +18,10 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"strings"
 	"testing"
 
+	"github.com/docker/docker/api/types/mount"
 	"gvisor.dev/gvisor/pkg/test/dockerutil"
 	"gvisor.dev/gvisor/pkg/test/testutil"
 )
@@ -55,3 +57,53 @@ func DebugLog(b *testing.B, msg string, args ...interface{}) {
 		b.Logf(msg, args...)
 	}
 }
+
+const (
+	// BindFS indicates a bind mount should be created.
+	BindFS = "bindfs"
+	// TmpFS indicates a tmpfs mount should be created.
+	TmpFS = "tmpfs"
+	// RootFS indicates no mount should be created and the root mount should be used.
+	RootFS = "rootfs"
+)
+
+// MakeMount makes a mount and cleanup based on the requested type. Bind
+// and volume mounts are backed by a temp directory made with mktemp.
+// tmpfs mounts require no such backing and are just made.
+// rootfs mounts do not make a mount, but instead return a target direectory at root.
+// It is up to the caller to call the returned cleanup.
+func MakeMount(machine Machine, fsType string) ([]mount.Mount, string, func(), error) {
+	mounts := make([]mount.Mount, 0, 1)
+	switch fsType {
+	case BindFS:
+		dir, err := machine.RunCommand("mktemp", "-d")
+		if err != nil {
+			return mounts, "", func() {}, fmt.Errorf("failed to create tempdir: %v", err)
+		}
+		dir = strings.TrimSuffix(dir, "\n")
+
+		out, err := machine.RunCommand("chmod", "777", dir)
+		if err != nil {
+			machine.RunCommand("rm", "-rf", dir)
+			return mounts, "", func() {}, fmt.Errorf("failed modify directory: %v %s", err, out)
+		}
+		target := "/data"
+		mounts = append(mounts, mount.Mount{
+			Target: target,
+			Source: dir,
+			Type:   mount.TypeBind,
+		})
+		return mounts, target, func() { machine.RunCommand("rm", "-rf", dir) }, nil
+	case RootFS:
+		return mounts, "/", func() {}, nil
+	case TmpFS:
+		target := "/data"
+		mounts = append(mounts, mount.Mount{
+			Target: target,
+			Type:   mount.TypeTmpfs,
+		})
+		return mounts, target, func() {}, nil
+	default:
+		return mounts, "", func() {}, fmt.Errorf("illegal mount type not supported: %v", fsType)
+	}
+}